jharvell

Here is a photo of the existing panel. The new panel will be in the same location to take advantage of the crawl space vent. As you can see, I've already installed a 2" PVC conduit at the bottom. I am currently in the process of re-routing all the conductors that enter the panel through the other conduits so they all enter through the bottom conduit. Once that's done, I'll replace the panel. The new panel is much taller. So the conduit exiting the bottom of the new panel will immediately enter the conduit body. So my total conduit length with the new panel will be minimal. Much less than 2' so I won't have to de-rate ampacity. There are a couple of reasons I don't want to install individual conduits. I'm pretty sure I won't have room for all conductors to enter the bottom of the panel with multiple small conduits. This is a 3000 square foot house with one sub panel for upstairs. I'm planning to replace all existing branch circuits and feeders, with everything going into the crawl space first. I'll probably end up needing two 2" conduits or maybe even 3" Even if I do have room, I'll probably have to bend the conduits. But I want to use PVC instead of EMT since PVC won't corrode. Also, I don't think I will have enough height to do the bends. Also I am no good at bending EMT. I have a surge protector (see photo) that's going to take up space at the bottom. Click to Enlarge 48.13 KB

But if I don't clamp any of them then I won't comply with 312.5©. I do understand it's better not to bundle. I'll post a photo soon to show why separate conduits is a problem. I'm not sure if I would have room for all cables with your suggestion. I'll have to do some calculations.

OK, so each cable has to be securely fastened. But here's my problem. I'm upgrading the service at my house and the only reasonable place for the new panel is surface mounted on the exterior wall outside. The house is pier and beam and most of the branch circuits need to go into the crawl space. I want to enter the crawl space through the crawl space vent directly under the new panel. There really isn't enough room to run a separate conduit for each cable. What makes the most sense is to run a single 2" or 3" conduit into the crawl space. The total length would be less than 24" so I would not have to de-rate the ampacity. I just have to figure out how to secure the cables to the panel even though they all come in one large conduit. I thought of a cable clamp on the box adapter on the inside of the panel. But I don't think such a large clamp could grip the cables. Initially I will only have 10 12-2 cables, 1 8/3 cable and 1 6/3 cable entering this conduit. I thought of cutting two semi-circular cylinders of wood and running the cables between them so the clamp pushes them against the cables and grips everything. I'm worried the inspector is going to call it poor workmanship . Is there any reasonable way to secure the cables to the panel when there are few of them in one large conduit?